WPR creates etl file, WPA reports "Trace processing failed"

[0x8000ffff] An unknown error has occured.

Any clues?   Gpuview does not have a problem loading the same file. Win7 test system.

Here is the application event log entry associated with the failure:

Log Name:      Application
Source:        .NET Runtime
Date:          11/3/2011 5:25:08 PM
Event ID:      1026
Task Category: None
Level:         Error
Keywords:      Classic
User:          N/A
Computer:      mroddyte-w7-bed.lab.local
Description:
Application: wpa.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.Runtime.InteropServices.COMException
Stack:
   at Microsoft.Performance.Shell.WpaApplication.OpenFromEtlTrace(System.String, System.String[], System.String, Boolean)
   at Microsoft.Performance.Shell.WpaApplication.OpenUriOrPath(System.String, Boolean)
   at Microsoft.Performance.Shell.WpaApplication.OpenFile()
   at Microsoft.Performance.Shell.WpaMainWindow.<get_OpenCommand>b__2(System.Object)
   at Microsoft.Performance.UI.DelegateCommand.Execute(System.Object)
   at MS.Internal.Commands.CommandHelpers.CriticalExecuteCommandSource(System.Windows.Input.ICommandSource, Boolean)
   at System.Windows.Controls.MenuItem.InvokeClickAfterRender(System.Object)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate, System.Object, Int32)
   at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(System.Object, System.Delegate, System.Object, Int32, System.Delegate)
   at System.Windows.Threading.DispatcherOperation.InvokeImpl()
   at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(System.Object)
   at System.Threading.ExecutionContext.runTryCode(System.Object)
   at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode, CleanupCode, System.Object)
   at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object)
   at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object)
   at System.Windows.Threading.DispatcherOperation.Invoke()
   at System.Windows.Threading.Dispatcher.ProcessQueue()
   at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef)
   at MS.Win32.HwndWrapper.WndProc(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef)
   at MS.Win32.HwndSubclass.DispatcherCallbackOperation(System.Object)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate, System.Object, Int32)
   at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(System.Object, System.Delegate, System.Object, Int32, System.Delegate)
   at System.Windows.Threading.Dispatcher.InvokeImpl(System.Windows.Threading.DispatcherPriority, System.TimeSpan, System.Delegate, System.Object, Int32)
   at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr, Int32, IntPtr, IntPtr)
   at MS.Win32.UnsafeNativeMethods.DispatchMessage(System.Windows.Interop.MSG ByRef)
   at System.Windows.Threading.Dispatcher.PushFrameImpl(System.Windows.Threading.DispatcherFrame)
   at System.Windows.Threading.Dispatcher.PushFrame(System.Windows.Threading.DispatcherFrame)
   at System.Windows.Application.RunDispatcher(System.Object)
   at System.Windows.Application.RunInternal(System.Windows.Window)
   at System.Windows.Application.Run(System.Windows.Window)
   at Microsoft.Performance.Analyzer.Program.Main(System.String[])

Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name=".NET Runtime" />
    <EventID Qualifiers="0">1026</EventID>
    <Level>2</Level>
    <Task>0</Task>
    <Keywords>0x80000000000000</Keywords>
    <TimeCreated SystemTime="2011-11-03T21:25:08.000000000Z" />
    <EventRecordID>2772</EventRecordID>
    <Channel>Application</Channel>
    <Computer>mroddyte-w7-bed.lab.local</Computer>
    <Security />
  </System>
  <EventData>
    <Data>Application: wpa.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.Runtime.InteropServices.COMException
Stack:
   at Microsoft.Performance.Shell.WpaApplication.OpenFromEtlTrace(System.String, System.String[], System.String, Boolean)
   at Microsoft.Performance.Shell.WpaApplication.OpenUriOrPath(System.String, Boolean)
   at Microsoft.Performance.Shell.WpaApplication.OpenFile()
   at Microsoft.Performance.Shell.WpaMainWindow.&lt;get_OpenCommand&gt;b__2(System.Object)
   at Microsoft.Performance.UI.DelegateCommand.Execute(System.Object)
   at MS.Internal.Commands.CommandHelpers.CriticalExecuteCommandSource(System.Windows.Input.ICommandSource, Boolean)
   at System.Windows.Controls.MenuItem.InvokeClickAfterRender(System.Object)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate, System.Object, Int32)
   at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(System.Object, System.Delegate, System.Object, Int32, System.Delegate)
   at System.Windows.Threading.DispatcherOperation.InvokeImpl()
   at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(System.Object)
   at System.Threading.ExecutionContext.runTryCode(System.Object)
   at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode, CleanupCode, System.Object)
   at System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object)
   at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)
   at System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object)
   at System.Windows.Threading.DispatcherOperation.Invoke()
   at System.Windows.Threading.Dispatcher.ProcessQueue()
   at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef)
   at MS.Win32.HwndWrapper.WndProc(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef)
   at MS.Win32.HwndSubclass.DispatcherCallbackOperation(System.Object)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(System.Delegate, System.Object, Int32)
   at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(System.Object, System.Delegate, System.Object, Int32, System.Delegate)
   at System.Windows.Threading.Dispatcher.InvokeImpl(System.Windows.Threading.DispatcherPriority, System.TimeSpan, System.Delegate, System.Object, Int32)
   at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr, Int32, IntPtr, IntPtr)
   at MS.Win32.UnsafeNativeMethods.DispatchMessage(System.Windows.Interop.MSG ByRef)
   at System.Windows.Threading.Dispatcher.PushFrameImpl(System.Windows.Threading.DispatcherFrame)
   at System.Windows.Threading.Dispatcher.PushFrame(System.Windows.Threading.DispatcherFrame)
   at System.Windows.Application.RunDispatcher(System.Object)
   at System.Windows.Application.RunInternal(System.Windows.Window)
   at System.Windows.Application.Run(System.Windows.Window)
   at Microsoft.Performance.Analyzer.Program.Main(System.String[])
</Data>
  </EventData>
</Event>